O'Malley Jennifer T, Burgess Barbara J, Zhu Meng-Yu, Curtin Hugh D, Nadol Joseph B
Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Mass., USA.
Audiol Neurootol. 2014;19(3):184-92. doi: 10.1159/000358003. Epub 2014 Mar 27.
In our laboratory, human temporal bone specimens from patients who in life have undergone cochlear implantation are routinely processed with the implant in situ, embedded in Araldite, sectioned at 20 µm and serially photographed during cutting, stained with toluidine blue and mounted on glass slides. From the images, two-dimensional and three-dimensional reconstructions can be made and a very accurate implant insertion depth can be calculated from the three-dimensional reconstructions. However, this method precludes subsequent special stains and further molecular investigations of the tissue including proteomics and immunostaining, which is now possible with celloidin-embedded tissue. In this study, we correlated measurement of the implant array insertion depth calculated from histologic three-dimensional reconstruction with that measured from three-dimensional radiologic multiplanar reconstruction. Four human temporal bones with cochlear implants underwent postfixation preprocessing CT imaging with a Siemens Somatom Sensation Scanner. The CT scans from these four bones were downloaded into the Voxar software application, reformatted using the multiplanar reconstruction tool, viewed in three dimensions and measurements of intracochlear insertion lengths of the implants were obtained. The bones were processed routinely for in situ Araldite embedding, serial images were made of the block during sectioning, postprocessed using PV-Wave® software, aligned with Amira® software, and used to create histologic three-dimensional reconstructions. From these three-dimensional reconstructions, the insertion depth of the electrode array was mathematically calculated. The range of insertion depths was 15.9 mm (case 1) to 26.6 mm (case 4). The two methods, radiographic multiplanar reconstruction and three-dimensional reconstruction, differed by 0.4-0.9%. This provides confidence that important localization information about the electrode in situ can be gleaned from CT scans, thereby allowing us to extract the implants prior to processing for celloidin embedment and allow further techniques such as special stains and immunostaining to be accomplished in order to evaluate molecular mechanisms involved in cochlear implantation.
在我们实验室，取自生前接受过人工耳蜗植入术患者的人类颞骨标本，通常是将植入物留在原位进行处理，包埋于环氧树脂中，切成20微米厚的切片，并在切片过程中进行连续拍照，用甲苯胺蓝染色后装在载玻片上。通过这些图像，可以进行二维和三维重建，并且可以从三维重建中计算出非常精确的植入物插入深度。然而，这种方法排除了后续的特殊染色以及对包括蛋白质组学和免疫染色在内的组织进行进一步分子研究的可能性，而这些研究现在用火棉胶包埋的组织是可行的。在本研究中，我们将根据组织学三维重建计算出的植入阵列插入深度测量值与从三维放射学多平面重建测量得到的值进行了相关性分析。四块植入了人工耳蜗的人类颞骨，使用西门子Somatom Sensation扫描仪进行了固定后预处理CT成像。这四块骨头的CT扫描图像被下载到Voxar软件应用程序中，使用多平面重建工具进行重新格式化，以三维方式查看，并获得了植入物在耳蜗内插入长度的测量值。这些骨头按常规方法进行原位环氧树脂包埋处理，在切片过程中对组织块进行连续成像，使用PV-Wave®软件进行后处理，与Amira®软件对齐，并用于创建组织学三维重建。从这些三维重建中，通过数学方法计算出电极阵列的插入深度。插入深度范围为15.9毫米（病例1）至26.6毫米（病例4）。放射学多平面重建和三维重建这两种方法的差异为0.4 - 0.9%。这使我们相信，可以从CT扫描中获取有关电极原位的重要定位信息，从而使我们能够在进行火棉胶包埋处理之前取出植入物，并进行诸如特殊染色和免疫染色等进一步技术，以评估人工耳蜗植入所涉及的分子机制。
